Richard Dieter, executive director of the Death Penalty Information Center in Washington, D.C., cautioned that there could be a backlash.

“These ideas would jeopardize the death penalty because, I think, the public reaction would be revulsion,” he said.

Some states already provide alternatives to lethal injection. Condemned prisoners may choose the electric chair in eight states: Alabama, Arkansas, Florida, Kentucky, Oklahoma, South Carolina, Tennessee and Virginia. Inmate Robert Gleason Jr. was the most recent to die by electrocution, in Virginia in January 2013.

Arizona, Missouri and Wyoming allow for gas-chamber executions. Delaware, New Hampshire and Washington state allow inmates to choose hanging. The last U.S. hanging was in Delaware in 1996.

Utah is phasing out its use, but the firing squad remains an option there for inmates sentenced before May 3, 2004.

The firing squad is an option in Oklahoma, but only if lethal injection and electrocution are found unconstitutional.

Jackson Miller, a Republican in the Virginia House of Delegates, wrote a bill that would allow electrocution if lethal injection drugs are unavailable.

Miller said he would prefer that the state have easy access to the drugs needed for lethal injections. “But I also believe that the process of the justice system needs to be fulfilled.”